Merge branch 'jaeger-operation-cardinality' into 'master'

jaeger: limit operation cardinality by using route regex

See merge request gitlab-org/gitlab-workhorse!648

changelogs/unreleased/jaeger-operation-cardinality.yml

+---
+title: 'jaeger: limit operation cardinality by using route regex'
+merge_request: 648
+author:
+type: other

internal/upstream/routes.go

@@ -111,7 +111,7 @@ func (u *upstream) route(method, regexpStr string, handler http.Handler, opts ..
 	handler = denyWebsocket(handler) // Disallow websockets
 	if options.tracing {
 		// Add distributed tracing
-		handler = tracing.Handler(handler)
+		handler = tracing.Handler(handler, tracing.WithRouteIdentifier(regexpStr))
 	}
 
 	return routeEntry{